Regression of Atherosclerotic Plaques of Cholesterol-Fed Rabbits by Combined Chemotherapy With Paclitaxel and Methotrexate Carried in Lipid Core Nanoparticles

Abstract

In previous studies, it was demonstrated that lipid core nanoparticles (LDE) resemble the low-density lipoprotein structure and carrying the antiproliferative agent paclitaxel (PTX) strongly reduced atherosclerosis lesions induced in rabbits by cholesterol feeding. Currently, the aim was to verify whether combining LDE-PTX treatment with methotrexate (MTX) associated with LDE (LDE-MTX) could accelerate the atherosclerosis regression attained with single LDE-PTX treatment, after withdrawing the cholesterol feeding. Thirty-eight rabbits were fed 1% cholesterol chow for 8 weeks. Six of these rabbits were then euthanized for analyses of the aorta (controls). In the remaining rabbits, cholesterol feeding was withdrawn, and those 32 animals were allocated to 3 groups submitted to different 8-week intravenous treatments, all once/week: LDE-PTX (n = 10; 4 mg/kg), LDE-PTX + LDE-MTX (n = 11; 4 mg/kg), and LDE-alone (n = 11). Rabbits were then euthanized and aortas were excised for morphometric, immunohistochemical, and gene expression analyses. After cholesterol feeding withdrawal, in comparison with LDE-alone group, both LDE-PTX and LDE-PTX + LDE-MTX treatments had the ability to increase the regression of plaque areas: -49% in LDE-PTX and -59% for LDE-PTX + LDE-MTX. However, only LDE-PTX + LDE-MTX treatment elicited reduction in the intima area, estimated in -57%. Macrophage presence in aortic lesions was reduced 48% by LDE-PTX and 43% by LDE-PTX + LDE-MTX treatment. Matrix metalloproteinase 9 was reduced by either LDE-PTX (74%) or LDE-PTX + LDE-MTX (78%). Tumor necrosis factor α gene expression was reduced 65% by LDE-PTX and 79% by LDE-PTX + LDE-MTX. In conclusion, treatment with LDE-PTX indeed accelerated plaque reduction after cholesterol feeding; LDE-PTX + LDE-MTX further increased this effect, without any observed toxicity. These results pave the way for the use of combined chemotherapy to achieve stronger effects on aggravated, highly inflamed atherosclerotic lesions.

Targeting Inflammation With Nanosized Drug Delivery Platforms in Cardiovascular Diseases: Immune Cell Modulation in Atherosclerosis

“…In the aortic arch of ApoE −/− mice on HFD treated with MTX-NPs, 50% less coverage of plaques was found in comparison to the control group. Importantly, this result was obtained by injecting a dose four times lower than reported in literature (Leite et al, 2015 ; Gomes et al, 2018 ).…”

“…Canakinumab, a monoclonal antibody targeting interleukin-1β, was tested in the CANTOS (Canakinumab ANti-inflammatory Thrombosis Outcomes Study) trial (Ridker et al, 2011 , 2017 ). Moreover, the chemotherapeutic drug methotrexate (MTX), largely used as an immunomodulatory and anti-inflammatory (AI) drug, was described to lower the risk for total cardiovascular diseases in patients with chronic inflammation (Popkova et al, 2015 ; Gomes et al, 2018 ), and has been observed to inhibit atherogenesis and macrophage migration to the intima in animal models (Bulgarelli et al, 2012 ). Although its mechanisms of action are not fully clear, this molecule is capable of reducing the secretion of pro-inflammatory cytokines and the expression of adhesion molecules on both immune and endothelial cells (Coomes et al, 2011 ).…”

“…Active targeting was achieved also using a “biomimetic” approach: NPs can derive from, or have properties similar to, aggregates like LDL or HDL, naturally accumulating in AS plaques (Allijn et al, 2013 ; Duivenvoorden et al, 2014 ; Gomes et al, 2018 ). More specific tissue or cell targeting can be found testing nanoparticle libraries in-vitro or in-vivo (Kamaly et al, 2016 ; Tang et al, 2016 ), but the mechanisms of the found specificity should be understood, also in order to ensure it is preserved downhill of modifications of nanoconstructs or in different biological environments.…”

Repurposing existing drugs for cardiovascular risk management: a focus on methotrexate

“…This was associated with a reduction of macrophage presence in aortic lesions, matrix metalloproteinase 9, and TNF-α gene expression when compared to control animals. 61 …”

Methotrexate for Cardiovascular Risk Reduction: The Right Choice?

“…18 Concerning experimental models, in cholesterol-fed rabbits, methotrexate, in combination with paclitaxel, can cause regression of atherosclerotic plaques and decrease macrophage and matrix metalloproteinase 9 presence in these lesions as well as decrease tumor necrosis factor a gene expression. 19 Conversely, in rats with adjuvant-induced arthritis, methotrexate did not improve endothelial function. 20 The role of systemic inflammation (ie, high disease activity) contributing to accelerated CVD in patients with RA should not be ignored.…”